Black Marlin – Istiompax Indica – The most prized billfish in NZ waters

Big black marlin jumps the waves by Konstantin Gerasimov and depositphotos.com.
Big black marlin - Istiompax indica - jumps the waves by Konstantin Gerasimov and depositphotos.com.

Black Marlin – Istiompax Indica

By Allan Burgess

New Zealand is considered to be at the southerly limit of the black marlin’s Pacific range. They come here during the summer and autumn to feed on the huge abundance of baitfish close to shore around the upper half of the North Island. The black marlin is the rarest of the huge billfish that can weigh over 450kg. It is highly prized by big game anglers in our waters.

Scientific name: Istiompax indica. Previously Makaira indica. The species is currently classified in the genus Istiompax. 

Identifying Characteristics 

Although similar in appearance to the blue marlin, the aerofoil-like pectoral fins of the black marlin cannot be depressed down against the body without breaking the joints. It is the only species of marlin to have rigid pectoral fins making this a sure-fire way to identify a black marlin.  

An early photograph of a giant marlin weighing 970-pounds. Almost a Grander. The low dorsal fin and short sword suggests it is a black.
An early photograph of a giant marlin weighing 970-pounds. Almost a Grander. The low first dorsal fin and short sword suggest it is a black marlin. Date 1929. Photographer unknown. Courtesy of the Hocken Collections – Uare Taoka o Hakena – University of Otago, Library.

When viewed from above, the back and upper sides of the black marlin are dark cobalt blue rather than black as the name of the fish suggests. 

When hooked, the fish can have an almost fluorescent mauve-purple colouration over the back, upper head and cheeks. There can also be vertical blue stripes over the upper sides of the body. As the fish is played on the angler’s line this beautiful dazzling colouration is steadily lost. The upper body becomes more a dark purplish-blue and the undersides silver.

Once dead the upper body becomes a drab darkish grey and the undersides a lighter silvery grey.   

The black marlin has a stout solid elongated body with a shorter heavier bill than the other marlin species. The body is noticeably bulkier than the more plentiful striped marlin. It has two dorsal fins, two anal fins, a lunate caudal fin and two strong keels on the side of the caudal peduncle (base of the tail). The pelvic fins can be depressed into a groove.

The first dorsal fin when erect is less than 50% of the depth of the body. 

Black marlin - Istiompax indica. Watercolour by Allan Burgess.
Black marlin – Istiompax indica. Watercolour by Allan Burgess.

Temperature Range 

21°C – 30°C (70°F – 86°F). They are occasionally found in cooler temperate waters, such fish are usually very large specimens.

Distribution 

The black marlin is found in tropical and subtropical waters of the Pacific and Indian oceans. They are occasionally found in the Atlantic Ocean but are not known to breed there. 

When and Where to Find Black Marlin in New Zealand

The black marlin isn’t common in New Zealand waters with only around two dozen being caught even in a good year. Their scarcity value makes them highly sought-after and greatly prized by big-game anglers. 

Black marlin begins to appear in New Zealand waters from about December onwards. Tagging indicates that these fish have travelled here from their spawning grounds off Cairns, and Australia’s Great Barrier Reef where spawning takes place between September and November.

Black marlin, along with striped marlin and sailfish come in very close to shore in search of prey.  We know this because a few have even been caught by shore-based anglers fishing from rocky headlands both in Australia and South Africa. 

A surprising number of big blacks have also been caught relatively close to shore by New Zealand anglers fishing from trailer boats. 

In New Zealand waters black marlin is caught between January and May. The best months to fish for them are February and March.

They’re nearly always taken north of Taranaki on the West Coast and Gisbourne on the North Island east coast.

The best areas to catch them are, according to Sam Mossman in Serious About Gamefishing – Bluewater Techniques for New Zealand, Takeke Reef in the Cavalli Islands, Bird Rock to Cape Brett in the Bay of Islands, and in the Bay of Plenty, the Mercury Islands, The Alderman Islands, Mayor Island, Astrolabe Reef, the Penguin Shoals, Whale Island, and the Motu River area. On the North Island West Coast, the best spots to catch black marlin are the wide bars of the Manukau and Kaipara Harbours. 

How long does black marlin live for?  

Females live for about 12 years, but males only live for around 5 years.

Not all black marlin caught in New Zealand are huge fish. About half weigh between 100 and 200 kilograms.

Is black marlin good eating? 

Black marlin has firm white flesh that is considered to be very good eating. In Japan, the flesh commands high prices and is eaten raw in sashimi. Those that are landed in New Zealand are often smoked. Nowadays the trend is firmly toward tagging and releasing almost all billfish. 

The Heaviest Black Marlin World Record?

The heaviest black marlin recorded by the International Game Fish Association (IGFA) was taken by Edward Seay on 31 October 1969 off Cairns, Queensland, Australia. Taken on 50 lb. (24kg) line. The massive black weighed 509.84 kg (1,124 lb. 0 oz). A marlin weighing in excess of 1,000-pounds is often referred to as a “grander”. 

The largest marlin ever landed on rod and reel in accordance with IGFA rules was caught by Alfred C. Glassell, Jr, in Cabo Blanco, Peru on 4 August 1953. The giant black marlin weighed 707.61 kg (1560 lb. 0 oz) and was taken on a 60 kg (130 lb.) line.

Heaviest Black Marlin Landed in New Zealand

For some time the heaviest black marlin recorded in New Zealand waters was a fish that weighed 444 kg caught on 60 kg (130 lb.) tackle off Whakatane by Don Hague on 23 April 1978. 

Then on 9 February of 2002, Alain Jorion caught a black off Gisborne that tipped the scales at 473.2 kg (1043.2 lbs). Jorion’s fish is New Zealand’s first official Grander black marlin and the heaviest billfish of any species caught on rod and reel in this country.  

Females are heavier

Larger fish are females. Any fish weighing in excess of about 180 kg will be a female. Not all black marlin caught in New Zealand are huge fish. About half weigh between 100 and 200 kilograms. 

How fast are Black Marlin?

According to this program from BBC Earth they can swim at 80 mph (128 kph).

Black Marlin: The Fastest Fish on the Planet | Ultimate Killers | BBC Earth

What does black marlin eat?

Black marlin spends most of their time in warmer water near the surface of the ocean where they hunt a broad range of pelagic fish and squid including mackerel, mahi-mahi, flying fish, skipjack, bonito, trevallies, octopuses, and smaller marlin.  They most probably feed on whichever species are locally abundant in their location at the time. When far from shore they are often found to be feeding on small tuna. 

When close to shore black marlin feeds on a wide variety of different bottom-dwelling species. According to Sam Mossman, one fish captured in New Zealand waters was found to have a stomach full of spotties which are small inshore reef fish in the wrasse family.

Williamson Marlin Lure. Black Marlin lure.
Williamson Marlin Lure.

Black Marlin Fishing Methods

The black marlin is caught in New Zealand by trolling whole dead baits and skirted lures. Trolling lures at depth with the aid of downriggers has also proven successful.

Quite a few blacks have also been caught by drift fishing kahawai or small tuna live-baits. The typical method of catching them is to keep a lookout for marlin feeding on the surface, along with bait workups and bird activity, and quickly steer the boat to where the action is or was last seen. The bridle rigged life bait is then sent over the side and allowed to drift down.

When drift fishing either live or dead-baits anglers need to be prepared for anything. Such baits can also be taken by large tuna, kingfish, and sharks.

As an interesting aside, big black marlin have also been caught by Kiwi anglers live baiting for kingfish with heavy 37 kg tackle. Big blacks and blues have a tendency to dive deep and die late in the fight, leaving the angler with the unenviable task of having to haul their massive dead weight back up to the surface. Lighter gear in this situation would almost certainly result in a lost fish.

The Death of a Giant Marlin, Justified. Opinion: An Australian fisheries biologist explains why he believes the misinformation and misguided anger surrounding the death and weighing of a 1,431-pound black marlin misses the point. This article appears on sportfishingmag.com. If you have made it this far, I’m sure you will find it interesting.

References 

  1. The Australian Museum. About the black marlin. 
  2. Saltwater Gamefishing – Offshore and Onshore by Peter Goadby. Published by Collins New Zealand. First published 1991. ISBN 1-86950-040-7. Size: 300mm x 215mm. 342pp total. Many coloured, and black and white photographs, and line drawings. Hard cover. 
  3. The Complete Guide to Game Fishing by Glen Booth and Alister McGlashan. Hardback, ISBN 0732293561, 393 pages in colour. Hardback 290mm x 240mm. Harper Collins Publishers in 2011. 
  4. Collins Guide to the Sea Fishes of New Zealand by Tony Ayling. 48 Colour plates by Geoffrey J. Cox. Published by Collins 1982. There is also a slightly revised 1984 edition. Hardback. 198 x 130mm. ISBN 10: 0002169878 ISBN 13: 9780002169875. 
  5. New Zealand Fishes – Identification, Natural History, and Fisheries by Larry Paul. Published by Reed Publishing (NZ) Limited. First published 1986, Revised edition 2000. ISBN 0 7900 0654 5 Size: 250mm x 190mm. 253pp total. Many coloured, and black and white photographs, and line drawings. Hardcover. 
  6. Saltwater Game Fishing in New Zealand by Fred Wilkins with E.V. Sale. Published in 1982 by A.H. & A.W. Reed. ISBN 0-589-01404-8. Hardcover. 231pp. 
  7. Serious About Gamefishing – Bluewater Techniques for New Zealand by Sam Mossman. Published by David Bateman Limited. First published 2002. Size: 260mm x 200mm. 208pp. Over 200 photographs and line drawings. Hardcover. 
  8. Marlin Fishing by Bill Hall. Published by The Halcyon Press. First published 2002. SBN 1-877256-23-4. Hardcover with colour dust jacket. 367pp first edition, Size: 270mm x 195mm. Colour and Black and White photographs. 
  9. Grant’s Guide to Fishes. Guide to the fishes of Australia. ISBN: 978-0-646-14106-0. Format: Hardback Pages: 880. Weight: 2.5kg. Size: 25cm long, 18cm wide and 5cm deep.
  10. IGFA World Records. Edward Seay. Black Marlin 31 October 1969. Heaviest Record Catch. 509.84 kg (1,124 lb. 0 oz).

Video below. This must be the best drone footage of trolling and playing a black marlin on Youtube. Beautifully filmed and edited.

Here are a few highlights from our fishing trip to the Great Barrier Reef near Cairns / Cooktown Australia. All fish were released. It was an amazing experience and we could not be more satisfied.
 

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